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<table width="100%" summary="page for rock"><tr><td>rock</td><td style="text-align: right;">R Documentation</td></tr></table>

<h2>Measurements on Petroleum Rock Samples</h2>

<h3>Description</h3>

<p>Measurements on 48 rock samples from a petroleum reservoir.</p>


<h3>Usage</h3>

<pre>rock</pre>


<h3>Format</h3>

<p>A data frame with 48 rows and 4 numeric columns.
</p>

<table summary="Rd table">
<tr>
 <td style="text-align: right;">
        [,1] </td><td style="text-align: left;"> area  </td><td style="text-align: left;"> area of pores space, in pixels
        out of 256 by 256 </td>
</tr>
<tr>
 <td style="text-align: right;">
        [,2] </td><td style="text-align: left;"> peri  </td><td style="text-align: left;"> perimeter in pixels </td>
</tr>
<tr>
 <td style="text-align: right;">
        [,3] </td><td style="text-align: left;"> shape </td><td style="text-align: left;"> perimeter/sqrt(area) </td>
</tr>
<tr>
 <td style="text-align: right;">
        [,4] </td><td style="text-align: left;"> perm  </td><td style="text-align: left;"> permeability in milli-Darcies
    </td>
</tr>

</table>



<h3>Details</h3>

<p>Twelve core samples from petroleum reservoirs were sampled by 4
cross-sections.  Each core sample was measured for permeability, and
each cross-section has total area of pores, total perimeter of
pores, and shape.
</p>


<h3>Source</h3>

<p>Data from BP Research, image analysis by Ronit Katz, U. Oxford.
</p>


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